Las Trampas Regional Wilderness

18012 Bollinger Canyon Rd, San Ramon, CA 94583

Las Trampas Regional Wilderness is a regional park of 5,342 acres (21,62 km2), located in northern California's Alameda and Contra Costa counties. The nearest city is Danville, California Las Trampas for the traps, or the snares, is Spanish. The Park is part of the Eastern Bay Regional Park District (EBRPD).

General

It consists of two steep, hilly ridges (Las Trampas Ridge on the east and Rocky Ridge on the west) flanking a narrow valley along Bollinger Creek with a horse stable and parking for tourists. Some of the hiking trails include steep sections; they may involve a change in elevation of as much as 900 feet (270 m). The park was described as "the tough guy of the East Bay Regional Park District."

Vegetation on the southern and western slopes of the two ridges is predominant: black sage, shamise and buck brush, with smaller amounts of toyon, hybrid manzanitas, elderberry, gooseberry, chaparral currant, sticky monkeyflower, coffeeberry, coyote bush, poison oak, hollyleaf red berry, deer weed and dozens of other species. Some of the rocks exposed to it contain compressed fossil layers.

Rocky Ridge reaches 2.024 feet (617 m) above sea level. There is another trail at the elevation of 1,760 feet (540 m), that leads across EBMUD land. Take either the Valle Vista Staging Area on Canyon Road in Moraga or the Chabot Staging Area in Castro Valley to the south.

Chamise and Bollinger Creek Loop trails connect to Las Trampas Hill, east of Bollinger Creek. The range provides fantastic views over the valleys of Ygnacio, San Ramon and Amador, as well as Mt. Diablo and the Carquinez Straits.

There are two picnic areas next to the parking lot, named Steelhead and Shady. These are first-come, first-served and can not be reserved. The nearby Little Hills Picnic Ranch offers reservable picnic spots for groups of 50 to 300 people.

Trails

Bicycles are permitted on half the trails; hikers and equestrians on all the trails. Dogs are allowed to do so. It is likely to find goats, calves, steers and an occasional free-ranging bull on the trails; their grazing keeps the grass short for the safety of summer fire. Deer, coons, skunks, hawks, vultures and an occasional eagle can be seen. The most common trees are laurel in the California bay, and live oak on the coast. Other species include buckeye, broad leaf maple, live canyon oak, black oak, and scrub oak. The latter tends to prefer the ridgetop area at the end of Chamise Road, with its mistletoe.

The park encloses, on its eastern boundary, the triangular property of the National Historic Site of Eugene O'Neill on all three sides, with access from Las Trampas via hiking trails or from Danville by single-lane path. There are also some secluded waterfalls in the eastern portion of the park, most of which are difficult to access.

Las Trampas' western-slope section is a vulnerable watershed of the EBMUD (East Bay Municipal Service District), and is restricted to hiking by tourists who do not have a valid EBMUD permit.